The Bonn Scale BSABS

On the basis of the results of a follow-up study of 502 first admissions to the University Hospital in Bonn [11,13], Gross and colleagues constructed the Bonn Scale for the Assessment of Basic Symptoms (BSABS) [155], which includes subscales on ''dynamic deficiency'', cognitive disturbances of thought, perception and motor action, ''coenaesthesias'' and disturbances of the central autonomic nervous system and sleep disturbances. Each single item is rated by its closeness to positive symptoms in three degrees: (1) characteristic, which means the phenomenon observed is sufficiently similar to certain full-blown psychotic symptoms, (2) accompanied by a sense of strangeness, splitting or restlessness, and (3) associated with a delusional explanation. The instrument does not include a time matrix that would help to determine the gradient of change or timepoint and/or order of appearance, persistence and remission of symptoms.

The prodromal symptoms listed in the BSABS have attained the highest predictive power so far in predicting transition to psychosis, without taking the three degrees of intensity into account. Klosterkotter et al. [156] demonstrated transition from attenuated positive symptoms to full-blown psychosis in a descriptive design and predicted onset of schizophrenia in a prospective study over a mean follow-up period of 9.6 years [157]. Of a total of 338 patients who had been referred to any of the five German university hospitals participating in the study under various diagnoses because of suspected incipient schizophrenia, 160 patients who did not present psychotic symptoms at the initial assessment according to clinical records were followed up over a mean period of 9.6 years after first assessment. By the time of follow-up, 79 of these patients had fallen ill with DSM-IV schizophrenia - women on average after 4.3 years, men after 6.7 years [112]. Only two of these cases had not shown any basic symptoms at initial assessment, which yields a high sensitivity of 0.98 and a very low rate of false negatives of only 1.3%. Of the 81 patients who did not develop a DSM-IV schizophrenia during the study period, 33 had presented at least one basic symptom and 48 no basic symptoms. This corresponds to a rather high proportion of false negatives (20.6%) and a clearly lower specificity of 0.59. On the whole, however, a remarkably high proportion of the predicted outcomes were classified correctly (78%).

Klosterkotter et al. [112] also analysed the prognostic accuracy of the BSABS subsyndromes and found that ''information processing disturbances'' yielded the best result (PPP = positive predictive power: 0.77).

Information on the probands' diagnoses and other characteristics of this highly selected group at entry into the study is lacking. Therefore, it is unclear to what type of at-risk population the results are applicable. Nevertheless, several of the basic symptoms have been included in other early recognition instruments and are being subjected to further tests of validity.

BiPolar Explained

BiPolar Explained

Bipolar is a condition that wreaks havoc on those that it affects. If you suffer from Bipolar, chances are that your family suffers right with you. No matter if you are that family member trying to learn to cope or you are the person that has been diagnosed, there is hope out there.

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